The dynamic operation of affect and attending in tobacco smoking motivation are far from clear. To assess the effects of nicotine on affect priming the attentional bias towards competing emotions, a two-choice picture-viewing task was combined with an affective priming task. The event sequence included a 200 millisecond emotional priming picture (negative, positive, or neutral in valence), followed by a dual-target picture with one face in the left visual-field and another in the right visual-field. At least one of the two dual-target picture faces was either negative or positive. To assess the effects of nicotine on a traditional version of the affective priming task, another task sequence included a single, centrally located, target picture that followed the priming picture. Smokers completed the tasks in a repeated measures design wearing a nicotine patch on one day and a placebo patch on the other day. Consistent with hypotheses, there was a significant Nicotine × Prime Valence × Dual-Picture Valence interaction for the mean number of first gaze-fixations (FGFs). That is, both nicotine (relative to placebo) and positive (relative to neutral) priming pictures promoted increased FGFs towards positive and neutral emotional faces, while decreasing FGFs towards negative faces competing for attention. Nicotine (relative to placebo) and negative (relative to neutral) primes reduced FGFs towards negative faces, while increasing FGFs towards positive or neutral faces. In the traditional version of the affective priming task, as predicted, findings revealed that nicotine did not modulate evaluative performance. Nicotine (relative to placebo) promoted significantly increased levels of reported positive affect and decreased levels of negative affect. In addition to the development of a new paradigm to assess the effects of nicotine on affect and attending, the supporting literature is integrated to deepen the understanding of these processes in tobacco smoking motivation. The Affect-Priming hypothesis suggests that nicotine enhances the reinforcing value of positive stimuli, while attenuating the value of negative stimuli. Nicotine operates rapidly on the effectiveness of competing stimuli to attract attention.